The present invention relates to semiconductor device fabrication and integrated circuits and, more specifically, to field-effect transistor structures for a laterally-diffused metal-oxide-semiconductor (LDMOS) device and methods of forming a LDMOS device.
Device structures for a field-effect transistor generally include a body region, a source and a drain defined in the body region, and a gate electrode configured to switch carrier flow in a channel formed during operation in the body region. When a control voltage exceeding a designated threshold voltage is applied to the gate electrode, carrier flow occurs in an inversion or depletion layer in the channel between the source and drain to produce a device output current.
A fin-type field-effect transistor (FinFET) is a non-planar device structure that may be more densely packed in an integrated circuit than planar field-effect transistors. A FinFET may include a fin consisting of a solid unitary body of semiconductor material, heavily-doped source/drain regions formed in sections of the body, and a gate electrode that wraps about a channel located in the fin body between the source/drain regions. The arrangement between the gate structure and fin body improves control over the channel and reduces the leakage current when the FinFET is in its ‘Off’ state in comparison with planar transistors. This, in turn, enables the use of lower threshold voltages than in planar transistors, and results in improved performance and lowered power consumption.
High-voltage integrated circuits used, for example, in microwave/RF power amplifiers typically require specialized circuit technology capable of withstanding higher voltages. Laterally-diffused metal oxide semiconductor (LDMOS) devices are designed to handle higher voltages than logic field-effect transistors.
Improved field-effect transistor structures for a LDMOS device and methods of forming a LDMOS device are needed.